The present invention relates to cargo container liners , a coupling device as claimed in the dependent claim 7 and an method of unloading a container liner according to the invention.
Standardised containers or boxes extensively used for shipment of freight by land and sea, and the many advantages of such containers have made it extremely desirable to adapt them for use as many types of cargo as possible. Accordingly, there have been attempts, with varying degree of success, to use such standardised containers to carry bulk cargo such as dry bulk chemicals, powdered and pelletised resins, flour, coffee, cocoa and grains or other kinds of granular material.
When cargo containers are used to carry such bulk cargo, it is important that the container itself either be kept clean or be cleaned after each load of cargo is unloaded from the container, so that the container can subsequently be used for another load of cargo. Moreover, it is important to protect the bulk cargo from contamination and from undesirable exposure to the natural elements.
For these reasons, large plastic removable liners are often used to line the interior walls of surfaces in cargo containers that are used to carry bulk cargo. The liners protect the cargo during shipment, and after the container is delivered, the liner can be removed so that the container may be reused to carry other cargo without significant cleaning.
As it may be well understood, such liners are disposable. Consequently, the choice of materials used for the manufacture of the liners is critical with respect to e.g. costs of raw materials, environmental considerations with respect to the choice of raw materials, requirements from the human resources handling such liners in their daily work, etc.
One of the advantages and great potentials of such liners is that extensive hygiene requirements can be met in a simple and very effective way as cleaning can be effected very fast and relatively cheap. Thus, the process may be realised simply by disposing of an old liner and mounting of a new.
A serious drawback of the known liner systems is nevertheless that the great potential of the container lining concept has never been utilised optimally with respect to above mentioned possibilities. This may be acknowledged by a closer examination of the prior art liner concepts which primarily disclose so-called xe2x80x9copenxe2x80x9d systems with respect to the filling and discharging of such container liners. An xe2x80x9copenxe2x80x9d system is, according to the terms of the invention, a system wherein the filling or the discharge of the liners requires that the liners has to be opened and exposed to e.g. dirt, dust and other particles from the environment.
So far, the problems related to especially the discharge of the liners have been ignored.
Some attempts have been made to establish xe2x80x9cclosedxe2x80x9d systems addressing the discharge of the liners, as some liner types have been provided with integrated solid discharge tubes which are tailored to specially designed discharge pipe systems. One of the problems related to such containers is very heavy manufacturing costs. Another drawback of such liners is that the connection between the flexible liner and the tube tends to break when the discharging is effected, as the discharge of the liner creates very high stress and pressure levels on the weld seams. It should be noted that the weight of the materials to be unloaded through the discharge pipe might be several tonnes.
Another disadvantage of the above mentioned disposable liners having built-in discharge tubes is that the transport of the unused liners to the customers requires relatively high transport capacity, and, even more importantly, the collection and recycling becomes more complicated. Consequently, a huge unorganised accumulation of such container liners can be found at unloading locations.
A collapsible container liner comprising side walls defines an interior space, said liner having an upper and a lower portion, at least one of said walls comprising an opening communicating with at least one discharge tube being incorporated in the lower portion of said liner, said discharge tube or discharge tubes being fitted with releasable sealing means, said sealing means being accessible and releasable from the outside of said discharge tube,
said sealing means surrounding and tightening said discharge tube in its closed position, said sealing means providing access to the interior of the liner when released, a very advantageous container liner has been obtained.
Thus, the relatively simple technical provisions of the embodiment of the invention provide the possibility of utilising a closed-system discharge of a loaded liner. Thus, a simple release of the releasable sealing means blocking the discharge tube provides an opening of the liner, resulting in no physical contact with the interior of the container, as the discharge tube communicates with an opening to the interior of the container. Known discharge tubes are closed in the sense that the prefabricated opening has to be established manually by means of e.g. a knife, and thus implies contact with the interior of the container. Moreover, it should be noted that the opening system method results in a risk of adding dust, dirt etc. from e.g. the aforementioned knife to the unloaded material. This problem has effectively been dealt with due to the provisions of the invention.
A further important aspect of the invention is that the container liner may be incorporated in a very safe and reliable unloading system. This is due to the fact that the necessary strength of the end wall and the discharge tube of the liner may be provided with external support which is only added to the liner during the unloading process.
A further aspect of the invention is that the container liner may be conveniently pre-established by a qualified trained staff in such a way that the possibility of crucial breaking or leaking may not arise.
Said sealing means comprise a clamp or a string, a further advantageous embodiment of the invention has been obtained.
A string may thus be fitted onto the liner during the manufacturing process, and the string may be released and removed in a very simple way.
Said at least one discharge tube is closed by means of a permanent sealing, preferably at least one weld seam, at the outer end of said at least one tube, said sealing being breakable, a further advantageous embodiment of the invention has been achieved.
The use of permanent sealing at the outer end of the discharge tube provides additional security if the releasable sealing should accidentally break or leak during transport. The permanent sealing may easily be removed, e.g. by cutting away the part of the discharge tube being fitted with the sealing before initiating the unload procedure.
A container liner, according to the invention, may conveniently be arranged with the appropriate number of filling tubes. According to a preferred embodiment, the liner further comprises one filling tube and one ventilation tube arranged in the upper portion of the container liner, thus ensuring that the container liner can be operated in an overall loading and unloading closed system
A collapsible container liner comprises side walls defining an interior space
said liner having an upper and a lower portion,
at least one of said walls comprising an opening communicating with at least one discharge tube being incorporated in the lower portion of said liner,
at least one of said discharge tubes being closed by means of a permanent sealing, preferably at least one weld seam, at the end portion of said tube(s), said sealing being breakable, a further advantageous embodiment of the invention has been obtained.
The use of permanent sealing at the outer end of the discharge tube provides additional security if the releasable sealing should accidentally break or leak under transport. The permanent sealing may easily be removed, e.g. by cutting away the part of the discharge tube being fitted with the sealing before initiating the unloading procedure.
A container liner, according to the invention, may conveniently be arranged with the appropriate number of filling tubes. According to a preferred embodiment, the liner further comprises one filling tube and one ventilation tube arranged in the upper portion of the container liner, thus ensuring that the container liner can be operated in an overall loading and unloading closed system.
The discharge tube or discharge tubes is/are fitted with releasable sealing means, said sealing means being accessible and releasable from the outside of said discharge tube,
said sealing means surrounding and tightening said discharge tube in its closed position, said sealing means providing access to the interior of the liner when released, a further preferred embodiment of the invention has been obtained, as the synergy provides the discharge tube with both an outer permanent sealing and an inner releasable sealing for optimal loading, transport and unloading conditions.
Said sealing means comprise a clamp or a string, the aforementioned advantages having been obtained, a further advantageous embodiment of the invention has been obtained.
A coupling device for a discharge tube of a collapsible liner is fitted in a container, said coupling device having a mounting end adapted for directly or indirectly securing of said container
said coupling device further having a receiving end adapted for receiving a discharge pipe,
said receiving end defining an opening having a surrounding receiving surface
said receiving surface being adapted to secure an end section/portion of a discharge tube between the receiving surface of the coupling device and a corresponding receiving surface of a discharge pipe, when the coupling device is coupled and secured onto said discharge pipe, a very advantageous embodiment of the invention has been obtained.
The coupling device, according to the invention, should be compared to existing system wherein a plate, such as plywood, or complicated mechanical devices supported by the container or incorporated by the container liner itself will have to form a discharge device or support as such. All such known devices have to be arranged within the container or prefabricated with the liner before the container is loaded and do consequently form part of the cargo.
Thus, the fitting of a coupling device, according to the invention, may established after loading of a container liner and just before unloading. This means that no unnecessary cargo has to be transported together with the container.
Moreover, the fitting of the unloading device is established by means of a supporting coupling device to the container itself since purely mechanical couplings are relatively weak.
The mounting end and said receiving end are spaced in such a way that the discharge tube is directly or indirectly accessible between said ends, a further advantageous embodiment has been achieved, as an unhindered access to the discharge tube may be obtained.
This unique detail provides the possibility of a xe2x80x9cclosedxe2x80x9d system connection between the discharge tube of a liner and a discharge pipe, as sealing means, e.g. a simple string tied around the discharge tube of a liner, may be released after a completed coupling between the discharge tube and the discharge pipe. Consequently, the liner may be unloaded without actual external access to the liner and the load of the liner, such as cutting.
The receiving end has an open and closed position, and wherein said opening is formed by the receiving end in said closed position, a further advantageous embodiment has been obtained, as the arranging of the discharge tube in the coupling device may be obtained in a simple efficient way. The opening in the discharge tube may e.g. be formed by a hinged two-part opening, which may be locked into its closed position.
The securing means are adapted to be secured to retention bars fitted in the opening of a container, an further advantageous embodiment of the invention has been achieved. Thus, surprisingly, the retention bars provide the necessary support and strength in order to withstand the pressure on the coupling device due to unloading.
The simple fastening, according to the invention, should be compared to existing system wherein a plate, such as plywood, or complicated mechanical devices form a discharge device or support as such. All such known devices have to be arranged in the container before the container is loaded and thus form part of the cargo.
The said securing means comprise clamps adapted to correspond to at least two retention bars of a container, a further advantageous embodiment has been obtained, as the securing means may be mounted in a simple and user-friendly way. Moreover, the use of simple clamps, which may simply be clamped onto the retention bars, implies that no mechanical modification of the already known retention bars is necessary.
A further aspect is that the retention bars are designed to withstand relatively high pressures. Any modification of existing retention bars would involve a risk of weakening the strength significantly.
The securing means comprise clamps which are adjustably positioned on said frame, a further advantageous embodiment of the invention has been obtained. Thus, the securing means may be positioned relatively to fit exactly to the retention bars of the container, even though the vertical positioning of the retention bars is relatively inaccurate.
Said device comprises securing means adapted to be secured onto at least two protruding members at the end section of the frame of the opening on the container, an advantageous second embodiment of the discharge frame has been obtained, according to the invention. By securing the coupling device to the opening frame of the container, a particularly simple and solid attachment is possible. A coupling device, according to this second preferred embodiment, is particularly easy to mount as no hooking to the retention bars is required. Since the liner is often pressed up against the back side of the retention bars when filled, a hooking member for fastening the coupling device can be difficult to put in place without damaging the liner.
Said protruding members on the container are part of a door locking mechanism, the coupling device can easily be fitted onto a container without any prior adaptation to the opening frame of the container.
The securing means comprise a first and a second mounting bar that are essentially parallel with each other and provided with tightening means for clamping said bars onto the protruding members, a shiftable securing means is provided, making it possible to fit the coupling device to the left, right or central section of the opening without making any adaptations to the container frame or the coupling device. The tightening means are preferably designed as a threaded rod with a wing nut that can be tightened by hand.
The said mounting end comprises a support surface adapted to support the liner wall when the discharge tube is fitted in the coupling device, a preferred embodiment has been achieved. The function of the support surface is quite crucial, as this surface will prevent the breaking of the discharge tube due to the heavy pressures on the end wall of the liner, especially in the area around the discharge tube. According to this embodiment of the invention, the end wall of the liner may be supported by means of a simple and relatively small device, which may be fastened directly or indirectly onto the container without occupying an undue amount of space.
The unloading of a container liner comprises the steps of
fitting a coupling device, according to the invention, in the door opening of the container,
removing the permanent sealing of the discharge tube, if any
mounting the discharge tube of the liner in the coupling device in such a way that the end section/portion is secured between the receiving surface of the coupling device and a corresponding receiving surface of a discharge pipe, when the coupling device is coupled and secured to said discharge pipe,
releasing the releasable sealing means of the discharge tube, a very efficient and safe method of unloading a container liner has been obtained.
The unloading, according to the invention, implies a complete coupling of the discharge tube to the discharge pipe prior to removing the releasable sealing means, thus ensuring that the unloading may be effected as a closed-system operation. Reduced expenses with respect to the manufacturing also accompany the effective coupling, as rigid built-in discharge tubes have been avoided.